Use rubycas-client 2.2.1 to try to resolve rubycas#6

Author: garethrees

rubycas-client-rails.gemspec

@@ -14,5 +14,5 @@ Gem::Specification.new do |s|
   s.rubyforge_project = %q{rubycas-client}
 
   s.add_dependency('rails', '>= 3.0.0')
-  s.add_dependency('rubycas-client', '>= 2.3.5')
+  s.add_dependency('rubycas-client', '2.2.1')
 end